Want to speed up your flash video watching? By default, Firefox takes a sort of “snapshot” of whatever you are doing every ten seconds. Why? It is so that the browser can restore itself, just in case of a crash. Now you might ask, what does this have to do with flash videos? Well, the snapshot action is what is causing your ten second delay, at times, with watching flash videos on the Web.
The quick fix for this problem, at least for my own sake, is to increase the time between each of the saves performed by session restore.
By opening about:config in your Firefox address bar, then typing browser.sessionstore.interval in the filter box, you’ll see a value of 10000, which is in milliseconds. (Meaning your session is saved every 10 seconds.) I changed this to 300000, or every 5 minutes, as I don’t have the urgent need for tab restoration. If you feel like being more on the safe side, try increasing it to something a bit lower, say 120000, or every 2 minutes.
I gave it a shot, and it might not be a life changing experiance after doing so, but it does seem to make the videos play faster, especially if you have several Firefox tabs or windows open at the same time.